FIG. 1 (Prior Art) is a diagram of a conventional test system 10 for testing a power converter for defects. Test system 10 includes a first power converter 11, a second power converter 12, a voltage stabilization capacitor 13, an external load 14, and a data collection system 15. An Alternating Current (AC) source 16 supplies the first power converter 11. The data collection system 15 performs and configures a test cycle by communicating with the second power converter 12 via link 17. During a test cycle, the second power converter 12 is controlled to output a voltage and a current. Test cycles are performed by varying the output voltages and currents of the power converters. The test data is collected by the data collection system 15 and is used to determine whether the second power converter 12 operates as expected and is ready for field applications.
The current output by the second power converter 12 during the test cycle is supplied to an external load 14. In one example, the external load 14 is a resistive water heater element. In another example, the external load 14 is an air-cooled resistive load. The energy involved in load testing the second power converter 12 is primarily dissipated by the resistive load 14. As a result, load testing in the test system 10 results in significant power consumption. In addition, external load 14 is costly and consumes physical space in a lab facility. Moreover, each power converter to be tested requires a separate external load 14.
FIG. 2 (Prior Art) is a diagram of a conventional test system 20 that has improved power consumption over system 10. System 20 includes a power converter 21, a regenerative load 22, and a controller 23. During a test cycle, the power converter 21 supplies power to the regenerative load 22, and the regenerative load 22 provides power back to the converter 21. Although the test system 20 consumes less power during a test cycle than test system 10, test system 20 is expensive. Moreover, regenerative load 22 only affords use for testing power converters and consumes lab facility space. In addition, test system 20 provides for testing only a single power converter at a time resulting in testing throughput shortcomings. An improved solution is desired.